Winterizing

Tom,
What is the best material to use for a winter insulating skirtingaround a house that sits on a post foundation? Every year I see avariety of things used: plastic, bales of hay, bags of leaves,tarpaper, pieces of rigid foam insulation, boards. What is the bestmaterial for keeping the cold winter winds from blowing under thehouse, and what is the easiest to install? And what is the most mouse-proof?
Thanks.
M. Foucault
Cape Rosier

Hi,
The best thing to do, is insulate underneath the floor with foaminsulation. A minimum of R-25 is a good place to start. More is better. Youcan insulate in between the floor joists and then install full sheets offoam over bottom of the floor joists.If you do not fill the floor cavity with foam, leave the air space nearestthe upper area, nearest the living space. This is the only time a dead airspace actually does some good and is about an extra R-1 for each inch ofdepth.
This is preferable to insulating around the perimeter. If feel you mustinsulate the perimeter, you have to install a heavy piece of plastic on theground to minimize moisture in the sealed space.
Tom